A Biological Safety Cabinet (BSC) is a specific engineering control used in the biological laboratory to prevent exposure to or the contamination of biohazardous agents. BSCs should be used whenever there is a risk of splash or aerosol formation of biohazardous or potentially biohazardous materials. BSCs work by manipulating air flow surrounding the area where work is being done such that the majority of biohazardous aerosols generated inside the BSC remain in containment while the majority extraneous laboratory aerosols remain outside of containment.
BSCs are divided into three classes (I, II, III) with class II being subdivided into five types (A1, A2, B1, B2, C1). The type of cabinet to be used will depend on the Biosafety Level of the microorganism as specified by CDC-NIH guidelines. For Biosafety Level 1 (BSL-1) microorganisms, standard microbiological practices will provide adequate protection. However, if additional protection is desired, any class of cabinet may be used by personnel working with these microorganisms. Class I and II Biosafety Cabinets will be used for low to moderate hazard microorganisms of Biosafety Levels 2 and 3. The main difference between the two is that Class II cabinets provide protection to personnel and the microorganism and Class I cabinets only provide protection to personnel. The most commonly used BSC is the Class II Type A1 or A2 cabinet, a figure of which can be found below.
Class III Biosafety Cabinets (also known as Glove Boxes) are required when working with high hazard microorganisms at Biosafety Level 4 (BSL-4). These cabinets are totally enclosed to provide the highest possible protection to personnel and the microorganisms. Glove boxes are required for experiments using radioactive solids that may become airborne and with other highly toxic chemicals. Decontamination of the equipment must be performed prior to use of different materials/agents. Regardless of the type of research being conducted, it is important to follow safe practices and guidelines in order to minimize possible exposure. Listed below are some general BSC guidelines:
Biosafety Cabinet General Guidelines
- All individuals working with a BSC must be trained in the proper operation, disinfection, and safe practices before starting work.
- Ensure BSC is within certification date, this can be found on the certification sticker located on the front of the BSC. If BSC is not within certification date please notify the Office of Environmental Safety and Health. Never use a BSC that is not certified.
- Never store items on top of the biological safety cabinet.
- Never store items inside the BSC that impede or otherwise disrupt the airflow. BSCs may not be used for storage of materials when not in use.
- Always wear proper PPE as determined by risk assessment such as a gown, face/eye protection, a surgical mask, and a double set of gloves when working in a BSC.
- Never put your head inside the BSC, utilize mechanical devices to reach far areas.
- The BSC should be turned on at all times when working inside or when biohazardous agents are inside.
- The UV light should be turned off when working in the BSC as it can cause skin or eye damage.
- Always clean the BSC as well as other equipment before and after use. Note that a UV light, if present, does not provide adequate disinfection. All BSC disinfection procedures require the use of a facility approved disinfectant as determined by risk assessment.
- Always disinfect items (including gloved hands) before placing into or removing from the BSC. This applies even when items are within proper containment such as a leak proof container or other facility approved containment.
- Place all disinfected items required for the experiment, including biological waste containers within the biological safety cabinet before starting the experiment in order to minimize the movement of hands.
- Utilize aseptic technique at all times.
- Move arms using straight in and straight out movements, as opposed to sweeping arms in a sideways motion which displaces more airflow, creating turbulence.
- Flames in the cabinet can damage the HEPA filter, use flame with pilot light for momentary activation if absolutely necessary or use a micro-incinerator.
- Collect waste/sharps within the cabinet, use facility approved containers.
- If a spill occurs within the BSC, keep the unit running and immediately implement spill clean up procedures.
- A BSC does not provide the same level of chemical protection (if any) as Chemical Fume Hoods (CHF) when working with volatile chemicals.
- Laminar flow hoods and clean benches do not provide the same level of protection as biosafety cabinets. Under no circumstances may hazardous chemical or biohazardous material be used in a laminar flow hood. All laminar flow hoods and clean benches should have a notification sign denoting their incompatibility with hazardous materials.
The Centers for Disease Control and Prevention (CDC) requires Biosafety Cabinets be inspected annually. Environmental Safety and Health oversees the inspections and repairs through a certified third-party vendor. Departments will be billed for each piece of equipment that is inspected. Please contact UMBC ESH firstname.lastname@example.org (410) 455-2918 if your department has acquired a new BSC, if you have any questions, or if you would like to schedule an inspection.
More information on biosafety cabinets can be found utilizing the following resources